Detection of trends in moderate and heavy rainfall events in Chhattisgarh state

Abstract

The observed trends in moderate (25-50 mm per day) and heavy rainfall (50-75 mm, 75-100 mm and > 100 mm per day) events during southwest monsoon season and on annual basis in 26 districts of Chhattisgarh state was worked out and Mann- Kendall test has been applied to understand the significance the events. Results indicated that there is generally no significant trend of changes in the events under moderate and heavy rainfall events in most of the districts during southwest monsoon period as well on annual basis. However, significant increasing trend in 25-50 mm category has been noted in Bemetara, Korba and Kondagaon districts. On annual basis, significant increasing trend is found in Kawardha district while Balodabazar, Janjgir Champa, Koriya, Surajpur showed significant decreasing tendency under 50-75 mm category. The trend in number of days with 75-100 mm rainfall showed significant increasing trend in Bemetara and Mahasamund districts and significant declining trend is observed in Janjgir Champa, Kondagaon and Surajpur districts. Significant increasing trend was observed in Bemetara district under moderate and heavy rainfall events during southwest monsoon and on annual basis and it is suggested that creating new drainage canals and community tanks / check dams may assist the farming community to drain and to save the surplus rainwater during the heavy rainfall events.